Distinguishing intrahepatic cholangiocarcinoma from poorly differentiated hepatocellular carcinoma using precontrast and gadoxetic acid-enhanced MRI

Diagnostic performance of magnetic resonance imaging and contrast-enhanced ultrasound in differentiating intrahepatic cholangiocarcinoma from hepatocellular carcinoma: a meta-analysis

PURPOSE

To compare the diagnostic ability between magnetic resonance imaging (MRI) and contrast-enhanced ultrasound (CEUS) in distinguishing intrahepatic cholangiocarcinoma (ICC) from hepatocellular carcinoma (HCC).

METHODS

Original studies reporting the diagnostic accuracy of MRI and CEUS in differentiating ICC from HCC were identified in PubMed and EMBASE databases. Histopathological examination was used as the reference standard for tumor diagnosis. Study quality was assessed using QUADAS-2 scale. Data were extracted to calculate the pooled diagnostic sensitivity, specificity, and diagnostic odds ratio (DOR) using a bivariate random-effects model, as well as the area under the curve (AUC). Sensitivity analysis, subgroup analysis, meta-regression, and investigation of publication bias were also performed.

RESULTS

A total of 26 studies with 28 data subsets (18 on MRI, 10 on CEUS) were included, consisting of 4169 patients with 1422 ICC lesions and 2747 HCC lesions. Most MRI studies were performed at 3T with hepatobiliary agents, and most CEUS studies used SonoVue as the contrast agent. In MRI, the pooled sensitivity, specificity, DOR, and AUC in distinguishing ICC from HCC were 0.81 (0.79, 0.84), 0.90 (0.88, 0.91), 41.47 (24.07, 71.44), and 0.93 (0.90, 0.96), respectively. The pooled sensitivity, specificity, DOR, and AUC of CEUS were 0.88 (0.84, 0.90), 0.80 (0.78, 0.83), 42.06 (12.38, 133.23), and 0.93 (0.87, 0.99), respectively. Subgroup analysis and meta-regression analysis demonstrated significant heterogeneity among the studies associated with the type of contrast agent in MRI studies. No publication bias was found.

CONCLUSION

Both MRI and CEUS showed excellent diagnostic performance in differentiating ICC from HCC. CEUS showed higher pooled sensitivity and MRI showed higher pooled specificity.

Machine learning based on gadoxetic acid-enhanced MRI for differentiating atypical intrahepatic mass-forming cholangiocarcinoma from poorly differentiated hepatocellular carcinoma

PURPOSE

The study was to develop a Gd-EOB-DTPA-enhanced MRI radiomics model for differentiating atypical intrahepatic mass-forming cholangiocarcinoma (aIMCC) from poorly differentiated hepatocellular carcinoma (pHCC).

MATERIALS AND METHODS

A total of 134 patients (51 aIMCC and 83 pHCC) who underwent Gadoxetic acid-enhanced MRI between March 2016 and March 2022 were enrolled in this study and then randomly assigned to the training and validation cohorts by 7:3 (93 patients and 41 patients, respectively). The radiomics features were extracted from the hepatobiliary phase of Gadoxetic acid-enhanced MRI. In the training cohort, the SelectKBest and the least absolute shrinkage and selection operator (LASSO) were used to select the radiomics features. The clinical, radiomics, and clinical-radiomics model were established using four machine learning algorithms. The performance of the model was evaluated by the receiver operating characteristic (ROC) curve. Comparison of the radiomics and clinical-radiomics model was done by the Delong test. The clinical usefulness of the model was evaluated using decision curve analysis (DCA).

RESULTS

In 1132 extracted radiomic features, 15 were selected to develop radiomics signature. For identifying aIMCC and pHCC, the radiomics model constructed by random forest algorithm showed the high performance (AUC = 0.90) in the training cohort. The performance of the clinical-radiomics model (AUC = 0.89) was not significantly different (P = 0.88) from that of the radiomics model constructed by random forest algorithm (AUC = 0.86) in the validation cohort. DCA demonstrated that the clinical-radiomics model constructed by random forest algorithm had a high net clinical benefit.

CONCLUSION

The clinical-radiomics model is an effective tool to distinguish aIMCC from pHCC and may provide additional value for the development of treatment plans.

Contrast-Enhanced Imaging in the Management of Intrahepatic Cholangiocarcinoma: State of Art and Future Perspectives

Intrahepatic cholangiocarcinoma (iCCA) represents the second most common liver cancer after hepatocellular carcinoma, accounting for 15% of primary liver neoplasms. Its incidence and mortality rate have been rising during the last years, and total new cases are expected to increase up to 10-fold during the next two or three decades. Considering iCCA's poor prognosis and rapid spread, early diagnosis is still a crucial issue and can be very challenging due to the heterogeneity of tumor presentation at imaging exams and the need to assess a correct differential diagnosis with other liver lesions. Abdominal contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) plays an irreplaceable role in the evaluation of liver masses. iCCA's most typical imaging patterns are well-described, but atypical features are not uncommon at both CT and MRI; on the other hand, contrast-enhanced ultrasound (CEUS) has shown a great diagnostic value, with the interesting advantage of lower costs and no renal toxicity, but there is still no agreement regarding the most accurate contrastographic patterns for iCCA detection. Besides diagnostic accuracy, all these imaging techniques play a pivotal role in the choice of the therapeutic approach and eligibility for surgery, and there is an increasing interest in the specific imaging features which can predict tumor behavior or histologic subtypes. Further prognostic information may also be provided by the extraction of quantitative data through radiomic analysis, creating prognostic multi-parametric models, including clinical and serological parameters. In this review, we aim to summarize the role of contrast-enhanced imaging in the diagnosis and management of iCCA, from the actual issues in the differential diagnosis of liver masses to the newest prognostic implications.

Gadoxetate disodium-enhanced MRI for diagnosis of hepatocellular carcinoma in patients with chronic liver disease: late portal venous phase may improve identification of enhancing capsule

PURPOSE

To investigate added value of late portal venous phase (LPVP) for identification of enhancing capsule (EC) on gadoxetate disodium-enhanced MRI (GD-MRI) for diagnosing hepatocellular carcinoma (HCC) in patients with chronic liver disease (CLD).

METHODS

This retrospective study comprised 116 high-risk patients with 128 pathologically proven HCCs who underwent GD-MRI including arterial phase, conventional portal venous phase (CPVP, 60 s), LPVP (mean, 104.4 ± 6.7 s; range, 90-119 s), and transitional phase (TP, 3 min). Two independent radiologists assessed the presence of major HCC features, including EC on CPVP and/or TP (CPVP/TP) and EC on LPVP. The frequency of EC was compared on GD-MRI between with and without inclusion of LPVP. The radiologists assigned Liver Imaging Reporting and Data System (LI-RADS) v2018 categories before and after identifying EC on LPVP.

RESULTS

Of the total 128 HCCs, 74 and 73 revealed EC on CPVP/TP for reviewer 1 and 2, respectively. After inclusion of LPVP, each reviewer identified seven more EC [Reviewer 1, 57.8% (74/128) vs. 63.3% (81/128); Reviewer 2, 57.0% (73/128) vs. 62.5% (80/128); P = 0.016, respectively]. Sensitivities of LR-5 assignment for diagnosing HCCs were not significantly different in GD-MRI with or without LPVP for EC identification [Reviewer 1, 71.9% (92/128) vs. 72.7% (93/128); Reviewer 2, 75.0% (96/128) vs. 75.8% (97/128); P = 1.000, respectively].

CONCLUSION

Including the LPVP in GD-MRI may improve identification of EC of HCC in patients with CLD. However, LI-RADS v2018 using GD-MRI showed comparable sensitivity for diagnosing HCC regardless of applying LPVP for EC.

Imaging Spectrum of Intrahepatic Mass-Forming Cholangiocarcinoma and Its Mimickers: How to Differentiate Them Using MRI

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary hepatic malignancy, with mass-forming growth pattern being the most common. The typical imaging appearance of mass-forming ICC (mICC) consists of irregular ring enhancement in the arterial phase followed by the progressive central enhancement on portal venous and delayed phases. However, atypical imaging presentation in the form of hypervascular mICC might also be seen, which can be attributed to distinct pathological characteristics. Ancillary imaging features such as lobular shape, capsular retraction, segmental biliary dilatation, and vascular encasement favor the diagnosis of mICC. Nevertheless, these radiological findings may also be present in certain benign conditions such as focal confluent fibrosis, sclerosing hemangioma, organizing hepatic abscess, or the pseudosolid form of hydatid disease. In addition, a few malignant lesions including primary liver lymphoma, hemangioendothelioma, solitary hypovascular liver metastases, and atypical forms of hepatocellular carcinoma (HCC), such as scirrhous HCC, infiltrative HCC, and poorly differentiated HCC, may also pose a diagnostic dilemma by simulating mICC in imaging studies. Diffusion-weighted imaging and the use of hepatobiliary contrast agents might be helpful for differential diagnosis in certain cases. The aim of this manuscript is to provide a comprehensive overview of mICC imaging features and to describe useful tips for differential diagnosis with its potential mimickers.

Value of perfusion parameters histogram analysis of triphasic CT in differentiating intrahepatic mass forming cholangiocarcinoma from hepatocellular carcinoma

We aim to gain further insight into identifying differential perfusion parameters and corresponding histogram parameters of intrahepatic mass-forming cholangiocarcinoma (IMCC) from hepatocellular carcinomas (HCCs) on triphasic computed tomography (CT) scans. 90 patients with pathologically confirmed HCCs (n = 54) and IMCCs (n = 36) who underwent triple-phase enhanced CT imaging were included. Quantitative analysis of CT images derived from triphasic CT scans were evaluated to generate liver perfusion and histogram parameters. The differential performances, including the area under the receiver operating characteristic curve (AUC), specificity, and sensitivity were assessed. The mean value, and all thepercentiles of the arterial enhancement fraction (AEF) were significantly higher in HCCs than in IMCCs. The difference in hepatic arterial blood supply perfusion (HAP) and AEF (ΔHAP = HAP_tumor− HAP_liver, ΔAEF = AEF_tumor− AEF_liver) for the mean perfusion parameters and all percentile parameters between tumor and peripheral normal liver were significantly higher in HCCs than in IMCCs. The relative AEF (rAEF = ΔAEF/AEF_liver), including the mean value and all corresponding percentile parameters were statistically significant between HCCs and IMCCs. The 10th percentiles of the ΔAEF and rAEF had the highest AUC of 0.788 for differentiating IMCC from HCC, with sensitivities and specificities of 87.0%, 83.3%, and 61.8%, 64.7%, respectively. Among all parameters, the mean value of ∆AEF, the 75th percentiles of ∆AEF and rAEF, and the 25th percentile of HF_tumor exhibited the highest sensitivities of 94.4%, while the 50th percentile of rAEF had the highest specificity of 82.4%. AEF (including ΔAEF and rAEF) and the corresponding histogram parameters derived from triphasic CT scans provided useful value and facilitated the accurate discrimination between IMCCs and HCCs.

Role of noninvasive imaging in the evaluation of intrahepatic cholangiocarcinoma: from diagnosis and prognosis to treatment response

INTRODUCTION

Intrahepatic cholangiocarcinoma is the second most common liver cancer. Desmoplastic stroma may be revealed as distinctive histopathologic findings favoring intrahepatic cholangiocarcinoma. Meanwhile, a range of imaging manifestations is often accompanied with rich desmoplastic stroma in intrahepatic cholangiocarcinoma, which can indicate large bile duct ICC, and a higher level of cancer-associated fibroblasts with poor prognosis and weak treatment response.

AREAS COVERED

We provide a comprehensive review of current state-of-the-art and recent advances in the imaging evaluation for diagnosis, staging, prognosis and treatment response of intrahepatic cholangiocarcinoma. In addition, we discuss precursor lesions, cells of origin, molecular mutation, which would cause the different histological classification. Moreover, histological classification and tumor microenvironment, which are related to the proportion of desmoplastic stroma with many imaging manifestations, would be also discussed.

EXPERT OPINION

The diagnosis, prognosis, treatment response of intrahepatic cholangiocarcinoma may be revealed as the presence and the proportion of desmoplastic stroma with a range of imaging manifestations. With the utility of radiomics and artificial intelligence, imaging is helpful for ICC evaluation. Multicentre, large-scale, prospective studies with external validation are in need to develop comprehensive prediction models based on clinical data, imaging findings, genetic parameters, molecular, metabolic, and immune biomarkers.

Magnetic Resonance Imaging of Nonhepatocellular Malignancies in Chronic Liver Disease

Hepatocellular carcinoma (HCC) is the most common liver malignancy associated with chronic liver disease. Nonhepatocellular malignancies may also arise in the setting of chronic liver disease. The imaging diagnosis of non-HCC malignancies may be challenging. Non-HCC malignancies in patients with chronic liver disease most commonly include intrahepatic cholangiocarcinoma and combined hepatocellular-cholangiocarcinoma, and less commonly hepatic lymphomas and metastases. On MR imaging, non-HCC malignancies often demonstrate a targetoid appearance, manifesting as rim arterial phase hyperenhancement, peripheral washout, central delayed enhancement, and peripheral restricted diffusion. When applying the Liver Imaging Reporting and Data System algorithm, observations with targetoid appearance are categorized as LR-M.

Targetoid appearance on T2-weighted imaging and signs of tumor vascular involvement: diagnostic value for differentiating HCC from other primary liver carcinomas

OBJECTIVES

To evaluate targetoid appearance on T2-weighted imaging and signs of tumor vascular involvement as potential new LI-RADS features for differentiating hepatocellular carcinoma (HCC) from other non-HCC primary liver carcinomas (PLCs).

METHODS

This IRB-approved, retrospective study was performed at two liver transplant centers. The final population included 375 patients with pathologically proven lesions imaged between 2007 and 2017 with contrast-enhanced CT or MRI. The cohort consisted of 165 intrahepatic cholangiocarcinomas and 74 combined hepatocellular-cholangiocarcinomas, with the addition of 136 HCCs for control. Two abdominal radiologists (R1; R2) independently reviewed the imaging studies (112 CT; 263 MRI) and recorded the presence of targetoid appearance on T2-weighted images and features of tumor vascular involvement including encasement, narrowing, tethering, occlusion, and obliteration. The sensitivity and specificity of each feature were calculated for the diagnosis of non-HCC PLCs. Cohen's kappa (k) test was used to assess inter-reader agreement.

RESULTS

The sensitivity of targetoid appearance on T2-weighted images for the diagnosis of non-HCC PLCs was 27.5% and 32.6% (R1 and R2) and the specificity was 98.2% and 97.3% (R1 and R2). Among the features of tumor vascular involvement, those providing the highest sensitivity for non-HCC PLCs were vascular encasement (R1: 34.3%; R2: 37.2%) and obliteration (R1: 25.5%; R2: 29.7%). The highest specificity for non-HCC PLCs was provided by tethering (R1: 100%; R2: 97.1%) and occlusion (R1: 99.3%; R2: 99.3%). The inter-reader agreement was moderate to substantial (k = 0.48-0.77).

CONCLUSIONS

Targetoid appearance on T2-weighted images and features of tumor vascular involvement demonstrated high specificity for non-HCC malignancy.

KEY POINTS

• Targetoid appearance on T2-weighted imaging and signs of tumor vascular involvement have high specificity (92-100%) for the diagnosis of non-HCC PLCs, regardless of the presence of liver risk factors. • In the subset of patients with risk factors for HCC, the sensitivity of signs of tumor vascular involvement decreases for both readers (1.7-20.3%), while the specificity increases reaching values higher than 94.2%. • The inter-reader agreement is substantial for targetoid appearance on T2-weighted images (k = 0.74) and moderate to substantial for signs of tumor vascular involvement (k = 0.48-0.77).

Quantitative evaluation of focal liver lesions with T1 mapping using a phase-sensitive inversion recovery sequence on gadoxetic acid-enhanced MRI

Purpose

To determine the usefulness of T1 values measured using a phase-sensitive inversion recovery (PSIR) sequence for the diagnosis of focal liver lesions.

Method

The study enrolled 87 patients who underwent gadoxetic acid-enhanced magnetic resonance imaging (MRI) for assessment of 38 hepatocellular carcinomas, 33 hepatic hemangiomas, 30 metastatic liver tumors, and 14 hepatic cysts. PSIR was performed before and 15 min after contrast agent administration, and then the respective T1 values were measured and the T1 reduction rate was calculated. Wilcoxon matched-pairs signed-rank test was used to compare T1 values pre- and post-contrast administration in each tumor. The Kruskal-Wallis test and Dunn's post-hoc test were used to compare T1 values among all tumors pre- and post-contrast administration and the T1 reduction rate among all tumors.

Results

The T1 values measured before and after contrast enhancement were 1056 ± 292 ms and 724 ± 199 ms for hepatocellular carcinoma, 1757 ± 723 ms and 1033 ± 406 ms for metastatic liver tumor, 2524 ± 908 ms and 1071 ± 390 ms for hepatic hemangioma, and 3793 ± 207 ms and 3671 ± 241 ms for liver cysts, respectively. The T1 values obtained before and after contrast administration showed significant differences for all tumors except liver cysts (P <  0.0001). T1 reduction rate was not significantly different between hepatocellular carcinoma and metastatic liver tumor, but was significantly different among other tumors (P <  0.05).

Conclusions

T1 mapping using the PSIR sequence is useful to differentiate focal liver lesions.

Evaluation of Primary Liver Cancers Using Hepatocyte-Specific Contrast-Enhanced MRI: Pitfalls and Potential Tips

When radiologists interpret hepatic focal lesions seen on dynamic magnetic resonance imaging (MRI) scans, it is important not only to distinguish malignant lesions from benign ones but also to distinguish nonhepatocellular carcinoma (HCC) malignancies from HCCs. In addition, most major guidelines, including those of the American Association for the Study of Liver Disease, European Association for the Study of the Liver, and Korean Liver Cancer Association and National Cancer Center, allow for the noninvasive imaging diagnosis of HCC in at-risk patients. However, ~40% of HCC cases show atypical imaging features mimicking non-HCC malignancies. Furthermore, several benign and malignant lesions, such as flash-filling hemangioma and intrahepatic mass-forming cholangiocarcinoma, frequently look like HCC. In contrast, although multiparametric MRI options, including hepatobiliary phase and diffusion-weighted imaging, provide useful information that could help address these challenges, there remain several unresolved issues with regard to the noninvasive diagnostic criteria characterizing HCC. In this article, we discuss the typical imaging features and challenging situations related to primary liver cancers in MRI, while considering how to make a correct diagnosis. LEVEL OF EVIDENCE: 5 TECHNICAL EFFICACY STAGE: 3.

Surgical Indications for Hepatocellular Carcinoma with Non-hypervascular Hypointense Nodules Detected by Gd-EOB-DTPA-Enhanced MRI

BACKGROUND

The surgical indication for non-hypervascular hypointense nodules (NHVN) detected incidentally on gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (Gd-EOB-MRI) for classical hepatocellular carcinoma (HCC) is unknown. Our aim is to clarify the long-term outcomes in patients with this finding.

METHODS

We reviewed the cases of 290 HCC patients, including 66 patients with NHVN, who underwent Gd-EOB-MRI prior to hepatectomy, between October 2008 and December 2017 at our center. We divided the patients into three groups: a no-NHVN group, a treated NHVN group, and an untreated NHVN group.

RESULTS

There was no significant difference in (RFS) or overall survival (OS) between the no-NHVN and untreated NHVN groups (p = 0.103 and 0.103, respectively). There was no significant difference between these two groups after propensity score matching. Multivariate analyses showed that microscopic intrahepatic metastases and the size of the main classical HCC, the target tumor, were independent prognostic factors of overall survival, but the presence of non-hypervascular hypointense nodules was not. There was no significant difference in RFS or OS between the treated NHVN and untreated NHVN groups (p = 0.158 and 0.109, respectively).

CONCLUSIONS

Non-hypervascular hypointense nodules detected incidentally on Gd-EOB-MRI associated with targeted hypervascular HCC did not reflect prognosis of HCC after hepatectomy. Surgical procedures for classical enhancing HCC may be performed even if non-hypervascular hypointense nodules adjacent to the targeted HCC cannot be removed completely.

Hepatocellular carcinoma (HCC) versus non-HCC: accuracy and reliability of Liver Imaging Reporting and Data System v2018

PURPOSE

The Liver Imaging Reporting and Data System (LI-RADS) was created to standardize the diagnostic criteria for hepatocellular carcinoma (HCC) and has undergone multiple revisions including a recent update in 2018 (v2018). The primary aim of this study was to determine the diagnostic performance and interrater reliability (IRR) of LI-RADS v2018 for distinguishing HCC from non-HCC primary hepatic malignancy in patients 'at-risk' for HCC. A secondary aim was to assess the impact of changes introduced in the v2018 diagnostic algorithm.

METHODS

This retrospective study combined a 10-year experience of pathologically proven primary liver malignancies from two large liver transplant centers. Two blinded readers independently evaluated each lesion and assigned a LI-RADS diagnostic category, additionally scoring all relevant imaging features. Changes in category based on the reader-provided features and the new v2018 criteria were assessed by a study coordinator.

RESULTS

The final study cohort comprised 105 HCCs and 73 non-HCC primarily liver malignancies. LI-RADS had a high specificity for distinguishing HCC from non-HCC (89% and 90% for reader 1 and reader 2, respectively), and IRR was moderate to substantial for final LI-RADS category and most features. Revision of the LI-RADS v2018 diagnostic algorithm resulted in very few changes [5 (2.8%) and 3 (1.7%) for reader 1 and reader 2, respectively] in overall lesion classification.

CONCLUSION

LI-RADS diagnostic categories and features had moderate to substantial IRR and high specificity for distinguishing HCC from non-HCC primary liver malignancy. Revision of LI-RADS v2018 diagnostic algorithm resulted in reclassification of very few lesions.

Volumetric Apparent Diffusion Coefficient Histogram Analysis in Differentiating Intrahepatic Mass-Forming Cholangiocarcinoma From Hepatocellular Carcinoma

BACKGROUND

Accurate differentiation between intrahepatic mass-forming cholangiocarcinoma (IMCC) and hepatocellular carcinoma (HCC) is needed because treatment and prognosis differ significantly.

PURPOSE

To explore whether volumetric apparent diffusion coefficient (ADC) histogram analysis can provide additional value to dynamic enhanced MRI in differentiating IMCC from HCC.

STUDY TYPE

Retrospective.

POPULATION

In all, 131 patients with pathologically proven IMCC (n = 33) or HCC (n = 98).

FIELD STRENGTH/SEQUENCE

3.0T MRI/conventional T₁ -weighted imaging (T₁ WI), T₂ WI, and diffusion-weighted imaging (DWI) with b value of 800 sec/mm² , dynamic enhanced MRI with gadobenate dimeglumine.

ASSESSMENT

Dynamic enhanced MR images were analyzed by two independent reviewers using a five-point scale to determine the diagnosis. Volumetric ADC assessments were performed independently by two radiologists to obtain different histogram parameters for each lesion. Quantitative histogram parameters were compared between the IMCC group and HCC group. Diagnostic performance of dynamic enhanced MRI, volumetric ADC histogram analysis, and the combination of both were analyzed.

STATISTICAL TESTS

Intraclass correlation coefficient (ICC) analysis, independent Student's t-test, or Mann-Whitney U-test, receiver operator characteristic (ROC) curves analysis, and McNemar test.

RESULTS

The sensitivity and specificity for dynamic enhanced MRI to differentiate IMCC from HCC were 82.1% and 82.6%, respectively. For all volumetric ADC histogram parameters, the 75th percentile ADC (ADC_75% ) had the highest AUC (0.791) in differentiating IMCC from HCC, with sensitivity and specificity of 69.7% and 77.6%, respectively. When combining dynamic enhanced MRI with ADC_75% , the sensitivity and specificity were 82.1% and 91.9%, respectively. Compared to dynamic enhanced MRI alone, the specificity for combined dynamic enhanced MRI and ADC_75% was significantly increased (P = 0.008).

DATA CONCLUSION

Volumetric ADC histogram analysis provides additional value to dynamic enhanced MRI in differentiating IMCC from HCC.

LEVEL OF EVIDENCE

3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:975-983.

LI-RADS M (LR-M): definite or probable malignancy, not specific for hepatocellular carcinoma

LI-RADS v2017 introduces major changes to the diagnostic criteria for LR-M observations to better guide radiologists in the use of this malignant category designation. LR-M is intended to preserve the specificity of the LI-RADS algorithm for diagnosis of HCC while not losing sensitivity for diagnosis of malignancy. The purpose of this paper is to provide a brief background on LR-M, discuss the diagnostic criteria new to v2017, special considerations for its application, and management implications.

Added value of smooth hypointense rim in the hepatobiliary phase of gadoxetic acid-enhanced MRI in identifying tumour capsule and diagnosing hepatocellular carcinoma

OBJECTIVES

To examine the added value of considering smooth hypointense rim in the hepatobiliary phase (HBP) of gadoxetic acid-enhanced MRI as capsule appearance for diagnosing tumour capsules and hepatocellular carcinoma (HCC).

METHODS

A total of 377 hepatic lesions (330 HCCs, 35 non-HCC malignancies and 12 benign) were included from 345 patients who underwent resection after MRI between January 2008 and December 2011. Two radiologists assessed the presence or absence of conventional capsule appearance and smooth hypointense rim in the HBP, and categorized each hepatic lesion according to the Liver Imaging Reporting and Data System. Difference in diagnostic performance was evaluated using the generalized estimating equation method.

RESULTS

For identifying capsule, the sensitivity and accuracy of HBP hypointense rim were significantly higher than those of conventional capsule appearance (81.5 % vs. 57.8 % and 76.1 % vs. 59.4 %, respectively; P < 0.001). For diagnosing HCC, the sensitivity and accuracy of LR-5 or LR-5 V were significantly higher when the HBP hypointense rim was also considered capsule appearance (83 % vs. 72.7 % and 84.1 % vs. 75.1 %, respectively; P < 0.001), with the same specificity (91.5 %).

CONCLUSIONS

Regarding smooth hypointense rim in the HBP as capsule appearance could improve the detection of tumour capsule and the diagnosis of HCC.

KEY POINTS

• Identifying tumour capsule is important for diagnosis of hepatocellular carcinoma (HCC). • Gadoxetic acid-enhanced MRI provides hepatobiliary phase (HBP) images. • Smooth hypointense rim seen in HBP may represent tumour capsule. • Regarding smooth hypointense rim as capsule appearance may improve HCC diagnosis.

Differentiation of mass-forming intrahepatic cholangiocarcinoma from poorly differentiated hepatocellular carcinoma: based on the multivariate analysis of contrast-enhanced computed tomography findings

PURPOSE

We aim to gain further insight into identifying differential radiological features of mass-forming intrahepatic cholangiocarcinoma (mICC) from poorly differentiated hepatocellular carcinoma (pHCC) on contrast-enhanced computed tomography (CT).

MATERIALS AND METHODS

107 patients with pathologically confirmed mICC (n = 48) and pHCC (n = 59) who had undergone preoperative contrast-enhanced CT were enrolled. Qualitative analysis of CT images were evaluated for tumor demarcation, shape, presence of satellite nodules, capsular retraction, biliary involvement, intratumoral arteries, tortuous tumoral vessels, vascular invasion, portal vein tumor thrombus, arterial enhancement pattern, portal venous phase enhancement, and washout pattern. Quantitative analysis was performed for mean attenuation of tumor and tumor-to-liver contrast during each phase. The degree of arterial enhancement was graded based on quantitative measurements.

RESULTS

A lobulated shape, indistinct margin, peripheral rim enhancement in the arterial phase, and the presence of bile duct dilatation were CT features favoring mICC, whereas a round shape, partially indistinct margin, heterogeneous enhancement in the arterial phase, washout pattern and the presence of tortuous tumoral vessels were CT features favoring pHCC in the univariate analysis (P < 0.05). Tumor-to-liver contrast of pHCC was greater than that of mICC during the arterial phase (P = 0.015). In the multivariate analysis, bile duct dilatation, tortuous tumoral vessels, and a washout pattern were independent CT features for distinguishing between the two types. (P = 0.003, P = 0.003, P = 0.044, respectively).

CONCLUSION

The absence of a washout pattern and tortuous tumoral vessels and presence of bile duct dilatation are more indicative of mICC than of pHCC on contrast-enhanced CT.

Recent Advances in the Imaging Diagnosis of Hepatocellular Carcinoma: Value of Gadoxetic Acid-Enhanced MRI

Magnetic resonance imaging (MRI) using gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DPTA), or gadoxetic acid for short, is a hepatocyte-specific contrast agent which is now increasingly used for the detection and characterization of focal hepatic lesions, particularly in patients at high-risk of developing hepatocellular carcinomas (HCC). In fact, several recent guidelines now recognize gadoxetic acid-enhanced MRI (Gd-EOB-MRI) as the primary diagnostic imaging modality for the noninvasive diagnosis of HCC, although it must be noted that several major guidelines still include only extracellular contrast media-enhanced computed tomography and MRI. The primary merits of Gd-EOB-MRI lie in the fact that it can provide not only dynamic imaging, but also hepatobiliary phase (HBP) imaging which can lead to high lesion-to-liver contrast and give additional information regarding hepatocyte uptake via organic anion transporting polypeptides. This, in turn, allows higher sensitivity in detecting small HCCs and helps provide additional information regarding the multistep process of hepatocarcinogenesis. Indeed, many recent studies have investigated the diagnostic value of Gd-EOB-MRI for early HCCs as well as its role as a potential imaging biomarker in predicting outcome. We herein review the recent advances in the imaging diagnosis of HCCs focusing on the applications of Gd-EOB-MRI and the challenging issues that remain.

Application of Joint Detection of AFP, CA19-9, CA125 and CEA in Identification and Diagnosis of Cholangiocarcinoma

OBJECTIVE

To explore the application of joint detection of serum AFP, CA19-9, CA125 and CEA in identification and diagnosis of cholangiocarcinoma (CC).

MATERIALS AND METHODS

The levels of serum AFP, CA19-9, CA125 and CEA of both 30 patients with CC and 30 patients with hepatocellular carcinoma (HCC) were assessed. Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic effects of single and joint detection of those 4 kinds of tumor markers for CC.

RESULTS

The levels of serum CA19-9, CA125 and CEA in CC patients were higher than that in HCC patients,whereas that of serum AFP was significantly lower s. The area under ROC curve of single detection of serum AFP, CA19-9, CA125 and CEA were 0.05, 0.86, 0.84 and 0.83, with the optimal cutoff values of 15.4 ng/ml, 125.1 U/ml, 95.7 U/ml and 25.9 ng/ml, correspondingly, and the percentage correct single diagnosis was <79%. With joint detection, the diagnostic effect of combined AFP, CA19-9, CA125 and CEA was the highest, with an area under the ROC curve of 0.94 (95%CI 0.88~0.99).

CONCLUSIONS

Single detection of serum CA19-9, CA125 and EA is not meaningful. The sensitivity, specificity, the rate of correct diagnosis and the area under ROC curve of joint detection of AFP, CA19-9, CA125 and CEA are highest, indicating that the joint detection of these 4 tumor markers is of great importance in the diagnosis of CC.